1. Field of the Invention
This invention relates to vehicle suspensions and, in particular, to a steer axle and suspension assembly incorporating a diagonal suspension arm or link between the frame and steer axle assembly to provide lateral stability.
2. Discussion of Related Art
One conventional type of steer axle assembly includes an axle beam that extends across the vehicle transverse to parallel longitudinally extending frame rails of the vehicle frame and which supports ground engaging wheels on either side of the vehicle. The axle beam is suspended from the vehicle frame by one or more suspension members including suspension arms, springs and shock absorbers. The suspension must provide lateral stability to the axle beam to prevent undesirable lateral movement of the axle beam. One conventional suspension includes a track rod or panhard rod that extends transverse to the vehicle frame. The use of a panhard rod in a steer axle assembly is difficult from a packaging standpoint, however, given the engine and other components that are typically located proximate the steer axle assembly. Another suspension incorporates one or more leaf springs between the frame and axle beam. Flexing of the leaf springs provides roll stiffness, but the axle beam is subject to torsional deflection. Typical leaf spring suspensions also fail to adequately react brake torque.
The inventors herein have recognized a need for a steer axle and suspension assembly that will minimize and/or eliminate one or more of the above-identified deficiencies.